Sealed reclosable container having stacking features



Aug. 12, 1969 J- D. AL-ROY 3,460,711

SEALED RECLOSABLE CONTAINER HAVING STACKING FEATURES Filed July 15. 1963 4 Sheets-Sheet 1 FIG. I

INVENTOR.

JOHN D. AL-ROY ATTORNEY Aug. 12, 1969 J DAL-ROY 3,460,711

SEALED RECLOSABLE CONTAINER HAVING STACKING FEATURES Filed July 15. 1968 4 Sheets-Sheet 2 l N VEN TOR JOHN D- AL-ROY ATTORNEY:

Aug. i2, 1969 J. n. AL-ROY 3,460,711

SEALED RECLOSABLE CONTAINER HAVING STAGKING FEATURES Filed July 15, 1968 4 Sheets-Sheet 5 "I'll," I

INVENTOR.

JOHN D. AL-ROY ATTORNEY:

Aug. 12, 1969 J. D. AL-ROY 3,460,711

- SEALED RECLOSABLE CONTAINER HAVING STACKING FEATURES Filed July 15, 1968 4 Sheets-Sheet 4 INVENTUR.

JOHN D. AL-ROY BY W K; ATTORNEY: 2 v

United States Patent Oil ice 3,460,711 Patented Aug. 12, 1969 SEALED RECLOSABLE CONTAINER HAVING STACKING FEATURES John D. Al-Roy, Bloomfield, Conn., assignor to Monsanto Company, St. Louis, Mo., a corporation of Delaware Filed July 15, 1968, Ser. No. 744,946 Int. Cl. B65d 43/10, 21/00 US. Cl. 220-60 12 Claims ABSTRACT OF THE DISCLOSURE A container which includes a body and lid combination, each of which is stackable without 'wedging, the lid being of the insert type and scalable on the body in two areas which may be separated from each other by a closed air space. Lever means create a mechanical advantage which permits unlocking the lid from the body by an applied force which can be less than the sealing force holding the lid on the body, thus permitting tight interlocking of the parts while still maintaining the container easily openable. Both lid and body may be structurally reinforced against bending in the sealing portions thereof.

SPECIFICATION This application relates to a container and more particularly to a container body and sealing lid combination.

Thermoplastic containers having a body portion sealed by a snack-in lid are becoming increasingly useful in packaging applications of all types. The main requirements of such a package are that it be tightly scalable to protect the contents from the surroundings, yet be easily openable by the user and resealable in those cases Where all of the contents are not used after the initial opening. The parts should be easily formable to minimize production costs, and both the body and lid should be stackable to optimize storage space, and further should be stackable without wedging into or over each other since this prohibits trouble free dispensing of the individual parts from a stack in an automated packaging line.

Approaches toward satisfying the requirement of seal tightness to protect the contents have invloved the use of various auxiliary adhesives between the lid and body which unfortunately add an additional component to the package, as well as a sealing force which must be overcome by the user in removing the lid. Such adhesive therefore render the package that much more expensive to manufacture and more diflicult to open. To remove a lid held tightly in place required use of sufficient force by the user to directly overcome the force holding the lid on the body which in some cases was rather substantial. Some lids were sealed to the body only at spaced portions around the periphery of the container, the intent being to initiate lid removal in the area where there was no seal, but needless-to-say this resulted in a compromise between protection of the contents and ease of opening. Stackability of the lid and body has been achieved by separate means provided in addition to the structure by which the seal is maintained, thus rendering the container more complicated in design, and in some cases more difficult to manufacture.

It has now been found that this dilemma of difficulties has been effectively solved by the present invention. There is provided a lid and container body combination, each of which is stackable without wedging by means of the same structure which is utilized in the scaling function. Tight sealing is achieved in two areas of the container and a closed air space can be maintained between these areas to enhance sealing. Means may be provided to literally unlock the lid from the body without the user having to apply a force sufiicient to directly overcome the sealing force(s), thereby permitting extremely tight sealing contact between the mating parts. The lid is readily resealable on the body after initial opening.

Accordingly, an object of the present invention is to provide an improved container lid and body combination which avoids the prior art difficulties discussed above.

An additional object of this invention is to provide a container lid and body combination, each of which is stackable without wedging or tilting with respect to an adjacent unit within the stack.

A further object of this invention is to provide a container lid and body combination, each of which is stackable without wedging or tilting in the stack by utilizing the same structure for accomplishing this stacking feature which is used in the scaling function.

Another object of this invention is to provide a container lid having an easy opening feature.

An additional object of this invention is to provide an extremely tight sealing container which is easily openable by removing the lid in a manner which avoids having the user utilize strength in excses of the sealing force( s) holding the lid on the body.

An additional object of this invention is to provide a container lid and body combination wherein the sealing areas of each are reinforced.

A still further object of this invention is to provide a tight sealing, stackable container lid and body combination which can be manufactured at high production rates utilizing conventional thermoforming techniques.

These and other objects will in part be obvious and will in part appear hereinafter.

These and other objects are accomplished by providing a container comprising a body having a base, a side wall extending upwardly and outwardly from the periphery of the base to an open upper end and a rim which extends generally outwardly from the open upper end of the body. A resilient lid is provided having an end wall for covering the open upper end! of the body, a side wall extending upwardly from the periphery of the end Wall and a flange which extends outwardly from the top of the side wall around the periphery thereof. The body has a first sealing means portion in its side wall which may be an outwardly projecting groove below the open upper end which extends around the periphery of the body. The lid also has a first sealing means portion in its side wall which may be a bead or normally engaging the first sealing means portion of the body to propide a first seal of said body when in assembled relation. The body has a second sealing means portion in its rim which may be a portion thereof and the lid has a second sealing means portion in its flange which may be a downwardly inclined marginal portion for normally engaging the second sealing means portion of the body to provide a second seal of the body when in assembled relation. Means are provided in the lid outside the second seal, which may be a lift tab, for removing the lid from the body. The first sealing means portion of the body has a stacking means portion formed therein which may be an outside surface portion of the groove in the side wall for supporting the body in stacked relationship between the first and second sealing means portions of a similarly configured body. The first sealing means portion of the lid has a stacking means portion formed therein which may be an outer surface portion of the bead for supporting the lid in stacked. relationship between the first and second sealing means portions of a similarly configured lid.

The container may include lever means to aid in releasing the lid from the body, which includes one or more downwardly projecting depressions in the margin of the end wall of the lid, a section of the body side wall below the first sealing means portion thereof, and side wall and flange portions of the lid above the depression whereby the body side wall section below the first sealing means portion thereof acts as a pivot point against which an outer surface of the depressed portion abuts and about which the resilient lid side wall portion above the depressed portion is rotated when pressure is applied against the means for removing the lid from the body so as to discontinue the seal provided by the first sealing means portions of the body and lid.

The container may further include a cutout in the body rim which is alignable with a lift tab in the flange of the lid whereby initial separation of the lid from the body is achieved by pressing against the lift tab through the cut out. Strengthening ribs may be provided around the sealing portions of the lid and body.

In describing the overall invention, reference will be made to preferred embodiments illustrated in the accompanying drawings in which:

FIG. I is a top plan view of a container of the invention;

FIG. II is a partial, perspective exploded view with parts broken away of a lid and body combination of the invention illustrating a non-circular container design;

FIG. III is a partial, sectional, elevational view taken along line III-III of FIG. I;

FIG. V is a view similar to FIG. III taken along the line IVIV of FIG. I;

FIG. V is a view similar to FIG. IV illustrating a manner of opening the container of the invention;

FIG. VI is a partial, sectional, elevational view of a nested stack of the lids of FIGS. I and II illustrating one section of the periphery of the nested stack;

FIG. VII is a view similar to FIG. VI illustrating another section of the periphery of the nested stack; and

FIG. VIII is a partial, sectional, elevational view of a nested stack of the container bodies of FIGS. I and II.

With reference to the drawings wherein identical numerals refer to identical parts, there is shown in FIG. I a generally circular thin wall, plastic container indicated as 10, which may, as is apparent from FIG. II be noncircular. Container comprises (FIG. II) body 12 having a conventional substantially fiat base (not shown) and a side wall 14 extending initially upwardly and outwardly from the periphery of the base to an edge 16 defining an open upper end. Body 12 further has rim 18 which extends generally outwardly from the open upper end of the body. The outer margin of rim 18 comprises a second sealing means portion of body 12 to be more fully described hereafter. The junction of rim 18 with side wall 14 is herein equivalent to edge 16. Side wall as used in this context is means to encompass the sides of a multi-sided body as well as that of a circular body. Side 'wall 14 has a first sealing means portion formed therein a short distance below the open upper end of body 12, which may be an outwardly projecting groove 20 extending around the periphery of body 12. Groove 20 is defined by a stacking means portion comprising lower wall portion 21 which gradually tapers outwardly from side wall 14 to rounded surface 23 and by upper wall portion 25 which is reversely tapered inwardly from rounded surface 23. Between the first sealing means portion of body 12 in side wall 14 which, as shown, is groove 20, and the second sealing means portion of body 12 which, as shown, is the outer margin of rim 18, the body side wall has a portion which projects inwardly with respect to the groove beyond the plane of the inside surface of the lower portion by an amount which exceeds the thickness of side wall 14, in order to provide lateral clearance between the sides of adjacently stacked bodies as illustrated in FIG. VIII. Body 12 may further include a plurality of spaced outwardly projecting strengthening dimples 17 peripherally spaced around the junction 16 between rim 18 and the top end of side wall 14. These dimples serve to strengthen rim 18 against bending around its junction with the upper end of side wall 14.

Resilient lid 22 of the insert variety is provided for body 12 and has an end wall generally indicated as 24 for covering the open upper end of body 12 as typically illustrated in FIG. III. End wall 24 may be flat or have one or more bends therein extending around its periphery as illustrated by numerals 27, 29 and 31 to provide lid 22 with strength against outward bowing when the container, for example, must withstand internal pressure. A side wall portion 26 is provided in lid 22 which extends upwardly from the periphery of the end wall 24. Side Wall 26 has at its lower end adjacent the periphery of end wall 24 which is symbolized by 33, a first sealing means portion comprising head 28 (FIG. III) for normally engaging the first sealing means portion (groove 20) in the side wall of the body to provide a first seal of the body when in assembled relation. More specifically, bead 28 is adapted to compressively engage inner surface 32 of the upper groove defining wall portion 25 in the body side wall, along a first peripherally continuous line when the lid is in place on the body as illustrated in FIG. III. Lid 22 further has flange 35 extending outwardly from the top and around the periphery of the side wall 26. Flange 35 (FIG. III) of the lid has a second sealing means portion formed therein comprising a slightly downwardly inclined outer marginal portion 34 at an acute angle with the horizontal for normally engaging the second sealing means portion of the body (outer margin of rim 18) to provide a second seal of the body when in assembled relation. More specifically, flange marginal portion 34 is adapted to compressively engage the outer margin of rim 18 of the container body along a second peripherally continuous line when the lid bead 28 is engaged in side wall groove 20. These peripherally continuous sealing lines are substantially parallel to each other. Lid 22 may also have strengthening dimples 55 formed at spaced intervals around the periphery along the junction of flange 35 and side wall 26. Means are provided in the lid outside the second seal for removing the lid from the body comprising lift tab 36 in lid flange 32 laterally outside the second peripherally continuous line between the inclined portion 34 of lid flange 35 and the outer margin of body rim 18. As illustrated in FIGS. I and IV body rim .18 may have a cut out portion 38 aligned below lift tab 36 of the lid, whereby the lid may be lifted away from the body by pressing against the undersurface of lift tab 36 through cutout 38. When the container is non-circular it is preferred that a plurality of lift tab 36 and cutouts 38 be provided in or adjacent to the corners of the container.

When lid 22 is in place on body 12 as illustrated in FIG. III, there may exist a clearance or closed air space between the sealing parts which is represented by 40 in FIG. III, and which is confined on one side by the first uninterrupted peripherally continuous sealing line between lid bead 28 and the wall defining portion of container groove 20, and on the other side by the second uninterrupted continuous sealing line between the surface of inclined portion 34 of lid flange 32 and the upper surface of the outer margin of body rim 18. This closed air space 40 provides an additional resistance against leakage and provides an increase in the quality of the seal between the lid and body. Its function is explained by considering that some minute leakage may be expected beyond the first seal when a compressible fluid, for example, is being confined within the container. Continued further leakage beyond the first seal, however, is limited since space 4t) causes the fluid passing beyond the first line of seal to lose velocity pressure. Since the pressure of the fluid has dropped in clearance space 40, there is therefore less tendency for the fluid to force its Way beyond the second outer seal line. A similar result is obtained for the reverse flow situation from the ex terior to the interior of the container.

As an additional important feature of this invention, there may be provided in lid 22, lever means to aid in releasing the lid from the container body. This lever means includes one or more depressed portions 42 in the lid end Wall adjacent the junction of the end wall with the side Wall 26. Each depressed portion 42 is defined by an outer wall 43, an inner wall 45 which may be inclined as shown, and a bottom wall 47 joining the lower ends of outer and inner walls 43 and 45. Each depression 42 preferably has a peripheral contour which is parallel to that of the peripheral portion of the container in which it is located in order to avoid changing the overall pleasing appearance of the container. Each depression 42 further may have opposed end walls 47 and 49. As illustrated in FIG. IV an outer surface portion 46 of depressed portion 42 is adapted to rest against an additional portion of the lever means when the lid is in place on the body, i.e., a section of the body side wall 14 below groove 20. The lever means of the lid further comprises side wall and flange portions of the lid above each depression 42.

In removing the lid from its sealing position on the body, the outer wall 43 of depressed portion 42, as well as the side wall and flange portion of the lid above depression 42, act as a lever to create a mechanical advantage wherein the amount of force required to be applied by the user to remove the lid is less because of the lever effect than the resisting clamping type of force being maintained along the first seal line between the bead and groove in the lid and side wall of the body. More specifically, and as illustrated in FIG. V, to remove the lid, pressure is initially exerted by a finger against the lower surface of lift tab 36 in order to move inclined portion 34 of the resilient lid away from the container rim back toward the container axis. However, in so doing, this may force bead 28 into tighter compressive contact with the wall of groove 20. The lid side wall portion, flange portion and outer wall of the depressed portion are so constructed as to remain relatively rigid during this movement, with outer surface portion 46 of depressed portion 42 contacting a portion of the body side wall. As shown in FIG. V, dimples 55 assist in preventing the lid flange portion from bending back on the side wall portion, while ribs 48 which are more fully described hereafter aid in preventing the sides of the lid bead from folding in toward each other during opening, thus keeping the lid portion of the lever means as rigid as possible during opening, yet permitting the lid to be fabricated from relatively thin material. The body side wall portion serves as a fulcrum around which pivot the lid side wall portion, the flange portion and in this case the end wall of the depressed portion, with these three parts acting together as a lever. This results in a tension being exerted on the lid bead which increases as the lid flange is forced further toward the container axis so as to overcome the compressive force holding the lid bead against the wall of the body groove. This movement permits a mechanical advantage permitting forcible lifting of the sealing portion of the lid by a force applied through a lever means which is less than that holding the lid on the body.

After the lid has been disengaged from the body in one area of its periphery, it may then be simply peeled away from the remainder of the periphery by pulling upwardly on the lift tab with the fingers. In cases where there is an extremely tight fit between the lid and body, it may be necessary to repeat the above described unlocking action at another portion of the periphery where a second depressed lid portion is located. Resealing is readily achieved by placing the lid across the top of the body and pressing downwardly so as to force the lid head back into place within the body groove. The upper portion of the lid side wall and the lid flange are designed so that the dimension of the lid in its as molded condition identified as 50 in FIG. VI is slightly less than the dimension indicated as 52 in the upper end of the body in FIG. IV, so that due to the resilient nature of the lid two lines of sealing contact will be automatically established when the lid is forced downwardly onto the body.

As illustrated in FIGS. I and II the depressed portions of the lid end wall are peripherally spaced about the lid. Intermediate these depressed portions, there exists a marginal portion 54 of the lid end wall having formed therein a plurality of laterally extending strengthening ribs 48. As indicated, ribs 48 aid in maintaining the walls of the lid depressions spaced from each other during opening, and further aid generally in providing bend resistance in the peripheral area of the lid in a direction generally perpendicular to the axis of the container. This latter resistance is important in stacking the lids to avoid having the peripheral portion of one lid forced beyond and undesirably wedged into a lower stacked lid when pressure is applied on the stack from above.

The stacking features of the present invention are illustrated in FIGS. VI-VIII. With respect to lids 22, the first sealing means portion thereof comprising bead 28 has a stacking means portion formed therein comprising bottom surface 56 of bead 28 which extends around the full periphery of the lid, and rests against and overlies the inner margin 58 of the flange 35 between the first sealing means portion (groove) and the second sealing means portion (outer margin of the flange) of a similarly constructed lid situated below it in the stack formation. As mentioned, ribs 48 stiffen the resilient lids against flexing downwardly into each other so as to cause wedging when loaded from above. This is especially important in non-circular containers where, because of the configuration, there is a tendency of the sides intermediate the corners to flex outwardly when top loaded. Also, stacking without wedging is achieved by means of cooperation between a surface of the lid bead and the body rim, which are the same surfaces involved in the sealing function of the lid.

The function of the depressed lid portion as it relates to the stacking feature of the lid is depicted in FIG. VI. The outer surface 60 of outer wall 43 of each depressed portion, of which there are a plurality at spaced intervals around the periphery of the end wall, lies immediately adjacent a section of the upper portion of the side wall of a similarly constructed lid situated below it in the stack formation. Thus, if a lateral force should. inadvertently be applied to one or more lids in the stack during handling or capping, surface 60 of an upper lid will contact the upper portion of the side wall of the lower lid and thereby restrict further lateral movement of the upper lid with in the lower lid. The depressed portions therefore act in combination as a restraining ring to hold the lids in concentric relationship within the stack. This structure also permits stacking without requiring a support to limit lateral movement of the stack. This feature is also achieved without adding additional structure to the lid, since the depressed portions also function in the easy opening feature of the container.

FIG. VIII illustrates the manner in which the container bodies 12 are stacked one within the other without wedging, by maintaining the side and bottom walls of each spaced from the portions of an adjacent similarly constructed body in the stack formation. The first sealing means portion of the body which is the groove in the side wall has an integral stacking means portion comprising lower wall portion 21 of the groove which supports the body on the curved surface in the side wall between the groove and the outer margin of the rim of a similarly constructed body lying immediately below it in the stack formation. This curved surface must be the innermost portion of the body in order that adjoining side walls of adjacently stacked bodies may be spaced from each other. Supporting contact between these surfaces is around the full periphery of the container. As in the case of the container lid, body stacking is achieved Without requiring additional structure, since the groove defining surfaces function in the sealing of the container.

The above description and particularly the drawings are set forth for purposes of illustration only and are not to be taken in a limited sense.

The lever means of the present invention includes a series of relatively rigid, integral adjoining members, i.e., a side wall portion, a flange portion and a depressed end wall portion which together function as a lever, along with a portion of the body side wall which functions as a fulcrum around which the lever pivots in removing the lid. The depressed portion of the lid end wall which extends below the groove in the body side wall when the lid is in place may be continuous around the entire margin of the end wall of the lid or may be discontinuous, i.e. provided at spaced intervals around the margin of the end wall of the lid. The lower end of the depression must be below the groove in the container body when the lid is in place thereon, in order that the outer corner wall of the depressed portion may act as the end of the lever which in turn acts upon the sealing force being applied between the depressed portion and the upper end of the body. The lateral width of the depression may vary, but must be suflicient so that its inner wall closest to the container axis does not obstruct the necessary inward movement of the outer wall of the depression during removal of the resilient lid. This width of the depressed portion defined as the distance between opposing top edges taken parallel to the side wall of the lid should be in excess of its opposing edge cross distance and should never exceed the maximum depth thereof. Though a depression may take any cross sectional form, an oblong shape is preferred.

Though the depression in the lid end wall has been described in combination with a body side wall section for disengaging a sealing bead from a retaining groove, it is likewise applicable to breaking any type of seal between a lid and body which is located between the lid depression and the outer limit of the container. For example, liquid sealants such as adhesives, lacquers and hot melts used in sealing a container may readily be broken by means of the structure of the present invention.

Though it is preferred when the lid is in place on the body that an outer surface section of the depressed portion abut against a side wall portion of the body, the latter acting as a fulcrum during removal of the lid, it may be possible to have the wall of the depressed portion of the lid spaced somewhat from this body side wall section if, during the initial pivoting movement of the lid sections constituting the lever, this wall of the depressed portion is caused to move outwardly and forcibly against the inner surface of the body side wall fulcrum portion.

The position in the longitudinal direction of the retaining groove in the body side wall may vary. It is preferred, however, that it be situated close to the upper end of the side wall. Location of the groove in this area of the side wall provides for the maximum smooth, continuous area below the groove for printing and application of decorative matter thereon. Since the wall defining the groove acts as a stacking means in the container body, location of the groove close to the upper end of the side wall permits one body to be stacked or nested deeply within another. This results in a low stack height which is defined as the distance between equivalent portions of adjacently stacked units. A low stack height permits optimum use of storage space and results in a stack which is unusually stable against lateral movement or tilting of one unit with respect to another in the stack.

At least portions of the lid wall surface defining the bead which seats within the groove when the lid is in place on the body must be laterally outside the junction between the upper end of the lid side wall and the lid flange, in order that these bead defining portions of the lid may be supported along the inner periphery of the flange of an adjacent lower stacked lid. It is preferred that the outer end of the bead be less than inch outside the peripheral junction of the lid side wall and lid flange.

The container of the present invention is equally ap plicable to circular as well as non-circular shapes. Possible configurations include square, oblong, oval, triangular and the like.

The material from which the container is formed may be any plastic capable of being molded from sheet material. Therrnoplastics generally have the advantages of being tough, difficult to break under ordinary circumstances, and have sufficient strength to be fabricated relatively thinly from web stock for economy purposes, since the containers contemplated herein are of the throwaway type which are generally meant to be nonreusable after consumption of the initial contents. The resulting lid and body when formed in this manner are unitary in construction, have no seams, and are of the thin wall variety having a generally uniform thickness of between about 2 to mils throughout the formed parts.

Usable thermoplastics are polymers based on styrene and acrylonitrile, polyolefins such as, for example, polyethylene or polypropylene and mixtures of the same.

It is conceivable that a body of one material could be used in conjunction with a lid of a different material in order, for example, to obtain a lid having a resiliency which exceeds that of a more rigid body. Such a combination could be a polyethylene lid on a modified polystyrene body. Particularly useful thermoplastics for forming these containers are relatively stiff materials such as, for example, rubber modified polystyrene or polystyrene which preferably has incorporated a rubber compound grafted or mechanically blended therein, e.g., acrylonitrile, butadiene, styrene copolymers. These relatively stiff materials give excellent reproducibility in thermoformed parts, are tough and resilient even when thin and kept at low temperatures, and are usually inert to most foods which may be packaged in the container.

In general, the present insert type of lid and container body combination find particular utility in automated and semi-automated packaging lines for foods and other consumer items, and wherever space requirements dictate that a plurality of lids in telescoping relation must be stored. The assembled container comprising the lid and container body is extremely tightly sealed, yet easily openable and resealable. The lids may be easily dispensed with little or no difliculty from the bottom of a stack, while at the same time resisting any tendency of one to tilt With respect to another when in stacked formation. Conventional thermoforming techniques using thin sheeting may be used to finish form the sealing parts and consequently high manufacturing rates may be maintained at very low costs.

It will be understood that many variations and modifications of the embodiments herein described will be obvious to those skilled in the art, and may be carried out without departing from the spirit and scope of the invention as hereinafter claimed.

What is claimed is:

1. A container comprising:

(a) a body having a base, a side wall generally extending upwardly and outwardly from the periphery of the base to an open upper end and a rim which extends generally outwardly from the open upper end of the body;

(b) a resilient lid having an end wall for covering the open upper end of the body, a side wall extending upwardly from the periphery of the end wall and a flange which extends outwardly from the top of the side wall around the periphery thereof;

(c) said body having a first sealing means portion in its side wall and said lid having a first sealing means portion in its side wall for normally engaging each other to provide a first seal of said body when in assembled relation;

((1) said body having a second sealing means portion in its rim and said lid having a second sealing means portion in its flange for normally engaging each other to provide a second seal of said body when in assembled relation;

(e) means in said lid outside said second seal for removing the lid from the body;

(f) said first sealing means portion of said body having a stacking means portion formed therein for supporting said body in stacked relationship between the first and second sealing means portions of a similarly configured body; and

(g) said first sealing means portion of said lid having a stacking means portion formed therein for supporting said lid in stacked relationship between the first and second sealing means portions of a similarly configured lid.

2. The container of claim 1 including lever means to aid in releasing the lid from the body, said lever means comprising a depressed portion in the lid end wall adjacent the junction of the lid end wall with the side wall, a section of the side wall of the body below the retaining groove, side wall and flange portions of the lid above the depressed portion, whereby the outer surface of said depressed portion supported by said body side wall section acts as a pivot point about which said side wall and flange portions of the resilient lid are rotated in a-clockwise direction when pressure is applied against the means for removing the lid from the body so as to break the first and second seals of the body.

3. A container comprising:

(a) a body having a base, a side wall generally extending upwardly and initially outwardly from the periphery of the base to an open upper end, a rim which extends generally outwardly from the open upper end, said side wall including an outwardly projecting groove therein below the open upper end which extends around the periphery of the body, the portion of said side wall above said groove having a surface portion offset inwardly with respect to said groove, an outer surface portion of the wall of said groove being adapted to cooperate with the inwardly offset portion of the side wall of a similarly configured container to support said body in stacked relationship;

(b) a resilient lid having an end wall for covering the open upper end of the body, a side wall extending upwardly from the periphery of the end wall, said side wall having a bead therein adapted to engage an inner surface of the wall of the groove in the side wall of the body when the lid is in place on the body, a flange which extends generally outwardly from the top of said side wall around the periphery thereof, said flange having a downwardly inclined marginal portion adapted to engage the rim of the body when the bead is engaged in the groove, and a lift tab in said lid laterally outside said inclined marginal portion for removing the lid from the body, an outer surface portion of said bead being adapted to support said lid in stacked relationship on the flange of a similarly configured lid.

4. The container of claim 3 wherein the lid is configured such that an intermediate air space exists between said engaging bead and groove and said engaging flange and rim when the lid is in place on the body.

5. A one-piece, resilient, thermoplastic lid for covering the opening of a container body, said lid having an end wall, a side wall projecting upwardly from the periphery of the end wall and a flange projecting outwardly from the top of the side wall around the periphery thereof, said side wall having a sealing means portion formed therein adapted to seal the container body when in assembled relation, said end wall having a plurality of spaced downwardly projecting depressions in its margin adapted to coact with a portion of a container body when in assembled relation, whereby said container body portion acting as a fulcrum around which at least a portion of said flange and side wall may be pivoted to break the seal in removing the lid from the container body.

6. The lid of claim 5 wherein the distance between opposing top edges taken parallel to the side wall of the lid is in excess of its opposing edge cross distance.

7. The lid of claim 5 wherein the lid has a plurality of spaced laterally extending strengthening ribs in the end wall.

8. The lid of claim 5 wherein the junction of the lid side wall with the lid flange has a plurality of outwardly extending dimples therein to strengthen the flange from bending about said junction.

9. A container comprising:

(a) a four-sided body having a base, side walls extending upwardly and outwardly from the periphery of the base to an open upper end, a rim which extends outwardly from the tops of said side walls, said side walls including a retaining groove therein extending around the periphery of the body situated slightly below the open upper end, said groove projecting laterally outwardly from the side walls, said side walls having an inwardly extending shoulder therein between said groove and the open upper end, an outer surface portion of the wall defining said groove being adapted to support said body in stacked relationship upon an inwardly extending shoulder in side walls of a similarly configured body;

(b) a resilient lid having an end wall for covering the open upper end of the body, a side wall extending upwardly from the periphery of the end wall, said side wall having a sealing bead therein adapted to compressively engage an inner wall surface defining said retaining groove in the side wall of the body along a first peripherally continuous line when the lid is in place on the body, a flange which extends outwardly from the top of said side wall around the periphery thereof, said flange having a slightly downwardly inclined outer marginal portion adapted to eompressively engage the rim along a second peripherally continuous line which is parallel with said first peripherally continuous line when the lid head is engaged in the groove in the side wall, a portion of said lid flange laterally outside said second peripherally continuous line acting as a lift tab, an outer surface portion of said bead being adapted to support said lid in stacked relationship on the flange of a similarly constructed lid;

(c) lever means to aid in releasing the lid from the body, comprising wall sections of the end wall defining a depressed portion adjacent the junction of the end wall with the side wall, side wall and flange portions of the lid above said depressed portion of the lid, and a peripherally extending section of the side wall of the body below the retaining groove which is adapted to support an outer wall surface of the depressed portion when the lid is in place on the body, whereby the peripherally extending section of the side wall of the body acts as a pivot point around which said side wall and flange portions of the resilient lid above said depressed portion of the lid are rotated in a clockwise direction when pressure is applied against the flange of the lid so as to break the first and second peripheral seal lines between the lid and the body, said wall sections defining the depressed portion being situated laterally adjacent to and inside the upper portion of the side wall of a similarly configured lid when in stacked position, so as to limit lateral movement of said supported lid with respect to a lower similarly constructed supporting lid;

(d) said rim of the body having a cutout portion 1 1 aligned with a lift tab in the lid flange whereby the lid may be initially separated from the body by pressing through the cutout against the lift tab.

10. The container of claim 9 wherein the junction of the body rim with the body side wall has a plurality of dimples formed therein for strengthening the body rim against bending about said junction.

11. The structure of claim 9 wherein the container has a plurality of said rim cutout and flange lift tabs spaced from each other around the margin of the container.

12. The container of claim 11 wherein said cutout and lift tabs are located in the corner areas of the container.

References Cited UNITED STATES PATENTS 3,137,409 6/1964 Davis 220-97 3,335,901 8/1967 Ewards 22060 3,347,411 10/1967 Kalata et a1. 22097 3,362,565 1/1968 McCormick 22044 3,388,827 6/1968 Thanhauser 2206O GEORGE T. HALL, Primary Examiner U.S. Cl. X.R. 

